In certain types of surgical procedures, the use of surgical staples has become the preferred method of joining tissue and, as such, specially configured surgical staplers have been developed for these applications. For example, intra-luminal or circular staplers have been developed for use in surgical procedures involving the lower colon wherein sections of the lower colon are joined together after a diseased portion has been excised. Circular staplers useful for performing such procedures are disclosed, for example, in U.S. Pat. Nos. 5,104,025; 5,205,459; 5,285,945; and 5,309,927 which are each herein incorporated by reference in their respective entireties.
In general, a conventional circular stapler typically consists of an elongated shaft that has a proximal actuating mechanism and a distal stapler head mounted to the elongated shaft. The distal stapler head commonly consists of a fixed stapling cartridge that contains a plurality of staples configured in a concentric circular array. A round cutting knife is concentrically mounted in the cartridge interior to the staples for axial travel therein. Extending axially from the center of the cartridge is a movable trocar shaft that is adapted to have a staple anvil removably coupled thereto. The anvil is configured to form the ends of the staples as they are driven into it. The distance between a distal face of the staple cartridge and the staple anvil is commonly controlled by an adjustment mechanism that is mounted to the proximal end of the stapler shaft for controlling the axial movement of the trocar. Tissue that is clamped between the staple cartridge and the staple anvil is simultaneously stapled and cut when the actuating mechanism is activated by the surgeon.
When performing a lower colon procedure using a circular stapler, a portion of the intestine may be laparoscopically stapled using a conventional surgical stapler that is inserted through a trocar. The conventional surgical stapler serves to place multiple rows of staples on either side of the diseased portion of colon to be removed. The target or diseased section is simultaneously cut as the adjoining end of the colon is stapled. After removing the diseased portion, the surgeon typically inserts the anvil of the circular stapling instrument into the distal end of the lumen, distal of the staple line. This may be done by inserting the anvil head into an entry port cut into the distal lumen by the surgeon. The lower staple line is utilized to hold the tissue of the colon over the circular cartridge. This method seals both ends of the colon only to have the sealed portions cut through and removed. These intermediate step staple lines are only temporary and facilitate the next step in the procedure.
On occasion, the anvil can be placed transanally, by placing the anvil head on the distal end of the stapler and inserting the instrument through the rectum. Once the anvil has been installed in the distal portion of the intestine, the intestine is secured around the anvil shaft by what is known as a “purse string” suture. The proximal portion of intestine is similarly secured around the stapler head by a purse string suture.
Once the ends of the intestine have been secured around their respective components, the surgeon, through an appropriate trocar sleeve, may employ a grasping device to grasp the anvil shaft and attach it to the portion of the trocar protruding within the stapler head. The surgeon then closes the gap between the anvil and cartridge, thereby clamping the proximal and distal ends of the intestine in the gap. The surgeon next actuates the stapler causing several rows of staples to be driven through both ends of the intestine and formed, thereby joining the ends and forming a tubular pathway. Simultaneously, as the staples are driven and formed, the concentric annular knife blade is driven through the intestinal tissue ends, cutting the ends adjacent to the inner row of staples. The surgeon then withdraws the stapler from the intestine and the procedure is complete.
Such procedures and devices require the surgeon to install two purse string sutures which lengthens the time required to complete the surgical procedure. In addition, such procedures may at times cause tissue “bunching” during the tissue cutting/stapling process.
Various attempts have been made to retain colon and other tissues around the stapling device. For example, U.S. Pat. Nos. 5,309,927; 6,117,148; and 7,094,247 disclose various arrangements that, in general, employ fasteners, ligation members, rings, springs, etc. that are apart from the stapling device itself in an effort to retain the tissue in position. U.S. Pat. No. 5,669,918 discloses a mechanism that employs a grasper like arm to frictionally pin the tissue against the trocar shank. While such device is essentially self contained, the grasper arms may ultimately be unable to effectively retain the tissue in position in practice.
Thus, the need exists for devices and methods for reducing the time required to complete the surgical procedure as well as addressing other shortcomings and challenges associated with retaining tissue in position when employing circular stapler arrangements.
The foregoing discussion is intended only to illustrate some of the shortcomings present in the field of the invention at the time, and should not be taken as a disavowal of claim scope.